Digitizing Dinosaur Tracks

Illustration: Ziqi Yu

A UTSA-based team is changing the footprint of Texas paleontology

By Daniel Castella

Around 125 million years before the foundation of Texas, a different kind of society was roaming its vast canyons, fertile plains and lofty mountains: that of the dinosaurs. Now, a San Antonio-based group of geoscientists is studying—and digitizing—ancient tracks imprinted in the terrain of the Lone Star State to gain new insight into the environment and behavior of these prehistoric beasts.

“Texas dinosaur footprints have been studied since the 1930s but never in this detail,” said Dr. Thomas Adams, curator of paleontology and geology at the Witte Museum in San Antonio. “They occur in 24 separate counties, with multiple localities per county, and each one can have anywhere from one to 300 footprints, so we’re talking about thousands of tracks and hundreds of individuals over a long period of time.”

“There are things you can learn from dinosaur tracks that you can’t learn from skeletons,” said Dr. Dan Lehrmann, professor of geosciences at Trinity University and a key contributor to the project. “The trackways tell us about their behavior.”

It is this detail that makes trackways so important to study and sets them apart from other artifacts, such as bones.

“Bones are the remains of a dead animal, whereas footprints are the remains of a living animal, an example of a day in their life,” Adams explained. However, unlike bones, trackways are susceptible to degradation, both from natural erosion and human activity, and they will not be around forever without expert intervention.

“Our goal is twofold,” said Dr. Alexis Godet, UTSA professor and sedimentology expert. “We want to preserve the dinosaur tracks for future generations and future projects, and to understand the environment in which these dinosaurs lived.”

This dual purpose has led to this group’s greatest innovation and a huge step forward in the preservation of these ancient artifacts— an accurate, entirely digital 3D model. The team of geoscientists includes Godet, Adams and Lehrmann, as well as University of Kansas professor and paleoclimate expert Dr. Marina Suarez and a number of graduate and undergraduate student volunteers, including longtime members Dianna Price and Justin Sharpe.

“We spend some time cleaning the tracks before we do anything,” explained Price, the UTSA doctoral student leading the effort for digitization. “I fly a drone about 10 feet over the tracks and take hundreds of photos, as high resolution as the drone will let me. Back in the lab, I take those photos and stitch them together to create a model from them.”

A resource of such detail and scale has never before been created for Texas localities. It provides an invaluable tool not just for current and future research but also for education and preservation of relics that could well disappear without it. The project started in late 2014, when the team first began to collaborate on dinosaur tracks in Government Canyon State Natural Area.

In addition to the groundbreaking digital methodology, the team is also using other, more traditional research techniques, such as collecting samples and running tests. These geochemical processes are being conducted on UTSA’s main campus and provide valuable insight into the physical environment these dinosaurs inhabited.

“Using some mineralogical techniques, we can read in the rocks the type of climate and environment that those dinosaurs were living in,” Godet explained. This data, locked into the sediment for millions of years, could prove vital in understanding the climate of our planet, adding another piece to the climate puzzle that spans from the Mesozoic era to today.

The team is also using a more traditional approach to conservation in their fieldwork—rubber molding. “We use liquid rubber to collect a mold of a track without damaging the original fossil,” Adams explained. “The mold can then be used to make casts for study and display.” These molds will be included in the Witte’s permanent collection, while the original footprint stays in the rock where it has been for millions of years.

This method does have limitations, however—notably with size, as some of these prehistoric reptiles left enormous footprints that would require a lot of rubber to mold. This complication is just one of many the fieldwork team faces. Some of the challenges are unique to Texas.

“There’s a lot of layers to working in Texas compared to other places,” Suarez explained. “You have to tread more lightly and communicate with more people. Trying to figure out who owns the land, and who to contact gets a little bit complicated.”

Despite such challenges and the ongoing impact of the coronavirus pandemic, the team is passionate about the work. “Preliminarily, the results are very exciting,” Adams said. “We would like to expand it to as many locations as we can. Since we are doing this in such detail, it allows us to do something new to these track sites.”